1. Field of the Invention
The present invention relates to a method of processing the via in a dual damascene manufacturing. More specifically, the present invention discloses a method of processing the via in a Cu/Spin-on-dielectric (Cu/SOD) dual damascene manufacturing to avoid Cu peeling.
2. Description of the Prior Art
In Cu/SOD dual damascene manufacturing, the major factors to be considered are Cu oxidation and Cu peeling on the bottom surface of the via. Usually the Cu oxidation on the bottom surface of the via can be removed efficiently by using Reactive-Pre-Clean (RPC); on the other hand, the adhesion force between Cu and SOD can be efficiently improved by using Ar plasma treatment.
However, the above-mentioned two procedures cannot match up. If the RPC is performed first, the follow-up Ar plasma treatment will ordinarily increase the via resistance, and then decrease the yield. The drawback of the foregoing order mainly arises from the perpendicular direction of the Ar plasma with respect to the bottom surface of the via in the Ar plasma treatment, therefore damages the Cu surface. On the other hand, if the Ar plasma treatment is performed first, the follow-up RPC will reduce the adhesion force between Cu and SOD. Moreover, Cu on the bottom surface of the via will splash on the side wall of the via and then soon spread into the intermetal dielectric layer and cause the electric leakage of the intermetal dielectric layer.
Therefore there is the need for improvement in the method of processing the via in a dual damascene manufacturing.